Change grep -e to grep --all We want to reserve -e for future use and grep compatibility. I've changed every-match to all out of a general preference for shorter long option names where short options don't exist.

#!/bin/sh

hg init

echo "Is there an error message when trying to diff non-existing files?"
hg diff not found

echo "Is there an error message when trying to add non-existing files?"
hg add not found